Who is Baron Cosimo Piovasco di Rondo from The Baron in the Trees and what is their importance?

Cosimo takes to living in the trees in order to live his life in the way he determines is best. He enters them because he can no longer abide life in a household where his sister Battista is allowed to lavishly execute and serve to their family all of the creatures of the forest. His protest is not against eating animals, for he remains a hunter and meat-eater all his life. It is against the pleasure she takes in their death, and disrespect with which she serves them, displaying them horribly on the table in humiliating and grotesque arrangements. His relationship with the animals around him is very like that of the Native American tribes, killing only what is needed and using every part of the animal.